The TVTropes Trope Finder is where you can come to ask questions like "Do we have this one?" and "What's the trope about...?" Trying to rediscover a long lost show or other medium but need a little help? Head to Media Finder and try your luck there. Want to propose a new trope? You should be over at the Trope Launch Pad.
Stupidity Is the Only Option? Letting the spy plane live might not be stupid In-Universe, but it is if you have the player's external knowledge.
NB: Technically you still would have violated a direct order, which might make the outcome of doing so moot...
Edited by Bisected8 TV Tropes's No. 1 bread themed lesbian. she/her, fae/faerViolating a direct order is relevant, but if war is declared immediately afterward, I expect you'd be let off pretty lightly.
Maybe related to You Can't Thwart Stage One, or Script Breaking/Sequence Breaking, but none of them seem quite right.
Agree with Bisected8, the ace combat one would be a non example of this because there are extraneous factors like violation of orders leading to a Non-Standard Game Over
I think there's quite a bit of Hero Must Survive in this, but you might have a variant, or sister/sub trope in <Villain> Must Survive or <NPC> Must Survive outside of the normal Escort Mission context.
Edited by Scorpion451Sounds like Event Flag (in this case, someone is not considered a villain until an event show up)
MAX POWER KILL JEEEEEEEEWWWWW^ and ^^ makes sense to a point. But I feel like Villain Must Survive or NPC Must Survive would, if they existed as tropes, necessarily include the reasoning that the character is important in some way, either to plot or gameplay. In cases like I'm describing, the character will shortly either escape, never to be encountered again, or promptly be shot down when, a moment later, the order is given. But I suppose I should find an example that doesn't include military orders from a superior, since that adds extra context that isn't part of the core idea.
Edited by SolipSchismAh, I just found Plot Armor. The armor is especially prominent here, cuz you can try killing the character (since this is a game) and you won't succeed (though this is subverted once in Metal Gear Solid), until the right time.
MAX POWER KILL JEEEEEEEEWWWWWThat'd cover it. It's basically But Thou Must! enforcing Plot Armor by means of a Non-Standard Game Over.
Edited by Specialist290

Video Game trope: You're not allowed to kill a bad guy until they are revealed to be a bad guy. Only applies in games that let you kill neutral and/or allied characters; killing this character results in a Game Over.
Especially noticeable in cases when Fridge Logic reveals that, realistically, there should have been no negative consequences to killing him. In some cases, it makes sense; killing Bob before he was revealed to be evil might ruin any chance to actually catch him doing anything evil, and thus make you look like a murderer.
But in other cases, Bob is a friend of Alice, and just minutes after you killed Bob, Alice was scripted to expose her evil plan, which would have implicated Bob and you should have gotten off scot-free.
Example:
- In the first mission of Ace Combat 5: The Unsung War, you encounter an unidentified spy plane. Your boss initially forbids you to fire on it, but barely a minute later you are attacked by fighter planes that are obviously allied with the spy plane, which escapes during the fighting. At the end of the mission, war is declared. Logically, the fighters would have attacked even if you had shot down the spy plane, and war still would have been declared, instantly vindicating you. But until you are actually attacked, your guided weapons are disabled. It's still possible to fire on the spy plane with the unguided, nose-mounted machine gun—and destroying it before being told to open fire will result in an instant mission failure.
Edited by SolipSchism